Campaigners are concerned that the thousands of ivory products available in Britain are fuelling the illegal poaching of elephants in Africa and Asia. Investigators who compiled the report strongly criticised Britain for having the weakest controls in Europe over the trade in ivory.
They found that that illegal products in the form of jewellery, figurines and furniture were being freely sold in some of London's most famous market and antiques areas, such as Portobello Road and New Bond Street.
But they also warned that even legally sourced ivory contributes to the slaughter of elephants and urged people not to buy anything made from it.
The report, funded by Care for the Wild International and Save the Elephants, found that there were more outlets selling ivory in the UK than anywhere else in Europe.
In a single month's investigation, the ivory expert Dr Esmond Martin found 8,325 products at more than 700 outlets, including almost 200 items thought to have come from illegal sources such as recently killed elephants.
In contrast, only 1,303 items were found in France, 621 in Spain and 461 in Italy. Dr Martin was amazed at the scale of the market in the UK, which was believed to be relatively small.
Britain now has the ninth largest ivory trade in the world, with huge exports to America as well as a thriving domestic trade.
The world's elephant populations were reduced severely by illegal poaching in the 1970s and 1980s, prompting the Convention on International Trade in Endangered Species (Cites) to impose a ban on the ivory trade in 1989.
However, the EU allows the import and export of ivory items manufactured before June 1947, which are classed as antiques.
Dealers are required to show certification proving that the items they sell date back to before that date.
While the regulations are strictly adhered to in other countries, Dr Martin found that false certification was easily available in Britain and that many dealers also side-stepped the Cites and EU regulations. He said: "Traders told me that that they often didn't bother with the paperwork.
"They tell tourists travelling back to somewhere like the US to put the items in their hand luggage so they won't be questioned. The regulations in Britain are the weakest in Europe and that is of some concern because there is such a large market here."
He found Chinese traders selling what he believed was recently produced ivory on Portobello Road market stalls in west London.
Dr Martin was also thrown out of some shops and auctions when he asked about the origins of ivory products, adding to concerns that they came from elephants that had been killed since the Cites ban was imposed.
He said: "The majority of the products we found were technically legal, but my worry is that illegal products are coming in that are being mixed up with the pre-1947 stuff, and people do not know whether what they are buying has come from poached elephants."
Items ranged from £5 bracelets to ivory inlaid furniture costing more than £500,000.
There were 1.3 million African elephants in 1979 but now only 300,000, according to the wildlife charity WWF. The Asian elephant population has fallen from 100,000 in 1900 to as low as 35,000 today.
A spokeswoman for the Department for Environment, Food and Rural Affairs said the Government "continued to be vigilant" about the illegal trade and would study the report carefully.